Nanotube medical sensors appear safe and functional in lab animals

Nature : Carbon nanotubes wrapped in polymers can be used to test for the presence of a range of molecules in blood. The polymers are designed to attach to specific molecules. The nanotubes fluoresce naturally, but their brightness changes when they are attached to the target substance. This makes it easy to detect the presence of the substance as well as its concentration. Michael Strano of MIT and his colleagues have successfully tested the devices as both injections and subdermal implants in mice. The injectable devices can be used for detecting large molecules such as fibrinogen, which is involved in blood clotting, a process that is not easy to monitor with existing technologies. An implant for detecting nitric oxide, which was embedded in a hydrogel matrix, was functional in mice for more than a year with no local inflammation.